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Why Does My Heart Rate Drop So Low While I Sleep?
Last updated: October 2, 2026. Medically reviewed by Dr. Avinesh Bhar, Board-Certified Sleep Physician, SLIIIP.com.
Your heart rate drops low while sleeping mainly because your body needs less work from the heart at rest. In deep sleep, heartbeat and breathing slow to their lowest levels of the night. For most people, a low number on a sleep tracker is normal, especially for fit adults. Dr. Avinesh Bhar, Board-Certified Sleep Physician at SLIIIP.com, starts with two questions about a low nighttime heart rate. Does it come with symptoms, and are there signs of disrupted breathing?
A slow heart rate during sleep is usually a sign of a calm, resting body, not a problem. A low heart rate becomes a concern when it comes with symptoms, long pauses, or signs of sleep apnea.
SLIIIP’s board-certified sleep physicians can do sleep evaluations for sleep apnea. Virtual consultations in all 50 states. Home sleep tests shipped to your door.
Why Does Your Heart Rate Slow Down at Night?
Sleep moves through stages, and the heart follows along. According to the National Institute of Neurological Disorders and Stroke, your heartbeat and breathing slow in the lighter stages of non-REM sleep. In deep non-REM sleep, heartbeat and breathing slow to their lowest levels of the night.
REM sleep is different. NINDS notes that during REM sleep, heart rate and blood pressure rise to near waking levels. That is why a sleep tracker often shows the lowest numbers early in the night. Small bumps later on often match REM periods.
The nervous system drives this shift. At night, the “rest and digest” side of the nervous system takes over. It gently slows the heart while the body repairs and recovers.
What Is a Normal Heart Rate While Sleeping?
There is no single normal sleeping heart rate that fits everyone. A useful starting point is the daytime resting range. The National Heart, Lung, and Blood Institute states that most adults have a resting heart rate between 60 and 100 beats per minute.
NHLBI defines bradycardia as a resting heart rate slower than 60 beats per minute. During sleep, many healthy adults dip below that number. A sleeping heart rate under 60 is common and is often not bradycardia that needs treatment.
Your own pattern matters more than a single number. Compare your night readings with your usual baseline over several weeks. A sudden change from your normal pattern is more useful than one low reading.
Many everyday factors can nudge your sleeping heart rate up or down. A cool, dark bedroom and a regular bedtime tend to support deeper, calmer sleep. Alcohol, a late heavy meal, illness, or a hard workout late in the day can push the number higher. So a night with a higher reading followed by a lower one is not unusual.
Is a Low Sleeping Heart Rate Normal for Athletes?
Yes, a low heart rate during sleep is often normal for athletes and very fit people. NHLBI notes that some people, especially those who are young or physically fit, may normally have slower heart rates.
Regular endurance training makes the heart muscle stronger. A stronger heart can pump more blood with each beat. So it needs fewer beats to do the same job, both awake and asleep.
If you train hard and feel well, a low nighttime number on your watch is usually expected. Still, talk to a doctor if you notice new dizziness, fainting, or a sharp drop in exercise ability.
Can Medications Make Your Heart Rate Drop During Sleep?
Yes, some medicines can slow your heart rate, both day and night. Beta blockers are a common example. They are often prescribed for high blood pressure, heart conditions, or migraine prevention.
Other heart and blood pressure medicines can have a similar effect. Some eye drops for glaucoma contain beta blockers too. Bring a full list of your medicines to any visit about a low heart rate. If your heart rate dropped after you started a new medicine, tell the prescriber. Do not stop, skip, or change any prescribed medicine on your own because of a low heart-rate reading. Your prescriber can decide whether a change is safe.
Can Sleep Apnea Make Your Heart Rate Drop Too Low?
Sleep apnea is associated with episodes of slow heart rate during breathing pauses. When the airway closes, oxygen falls and the heart can slow sharply for a few seconds. In some people, these pauses are linked to longer gaps between heartbeats or brief heart block episodes.
This pattern looks different from a normal deep-sleep dip. A normal dip is smooth and steady. An apnea-related drop tends to repeat, often followed by a quick rise when breathing restarts.
We cover the mechanism in depth in our article on bradycardia and sleep apnea. For the broader picture, see how sleep apnea affects the heart.
What Should You Do About a Low Heart Rate Alert From Your Watch?
A low heart rate alert is a reason to look closer, not a reason to panic. Most wearables let you set your own alert threshold. A default setting may not fit a fit adult with a naturally low resting rate.
Here is a simple way to respond:
- Check how you feel. A low number with no symptoms is less worrying than one with dizziness or chest discomfort.
- Look at the timing. Alerts during deep sleep are common. Alerts while you are awake and active matter more.
- Look for a pattern. Repeated sharp drops followed by quick spikes can point to a breathing problem.
- Save screenshots. Share several nights of data with your doctor.
Keep in mind that wrist sensors are estimates. Our guide to wearable sleep trackers explains what these devices measure well and where they fall short.
How Does SLIIIP Fit In?
SLIIIP does not treat bradycardia or other heart rhythm problems. Your primary care doctor or cardiologist handles that side. SLIIIP’s sleep physicians look at whether a sleep disorder may be part of the picture.
If sleep apnea is suspected, the process starts with a virtual visit. A home sleep test can then record breathing, oxygen, and heart rate overnight. Results can be shared with your cardiologist so both sides of your care line up.
Watch: A doctor explains why sleep apnea is often misdiagnosed
When to See a Doctor
Call 911 if a slow heart rate comes with fainting, chest pain, severe shortness of breath, or confusion. These symptoms need emergency care right away.
Make an appointment with your primary care doctor or cardiologist if you notice:
- Dizziness or lightheadedness, especially when you get up at night
- Unusual tiredness or weakness that is new for you
- A low heart rate alert while you are awake and not resting
- A big change from your usual nighttime heart-rate pattern
- A low heart rate that started after a new medicine
A sleep evaluation may also help if the low readings come with loud snoring, gasping, or pauses in breathing. Dr. Avinesh Bhar, Board-Certified Sleep Physician at SLIIIP.com, recommends checking whether the drops repeat in a sawtooth pattern. If they do, and you also snore or wake up tired, he suggests asking about a home sleep test alongside your heart workup.
Insurance Accepted at SLIIIP
SLIIIP works with most major insurance plans, including Medicare, TRICARE (Humana Military), Aetna, Cigna, Humana, UnitedHealthcare, Blue Cross Blue Shield, Kaiser Permanente, Ambetter, MultiPlan, Beech Street, Allied, Alliant, NovaNet, Secure Health, Coventry Health Care, and Clover Health.
SLIIIP’s board-certified sleep physicians can do sleep evaluations for sleep apnea. Virtual consultations in all 50 states. Home sleep tests shipped to your door.
Frequently Asked Questions
Is it normal for my heart rate to drop while I sleep?
Yes. Heart rate naturally slows during sleep, most of all in deep non-REM sleep.
What is a normal resting heart rate for adults?
The NHLBI states that most adults have a resting heart rate between 60 and 100 beats per minute. Sleeping rates are often lower.
Is a sleeping heart rate under 60 dangerous?
Usually not. Many healthy adults dip below 60 during sleep, especially if they are physically fit.
What is bradycardia?
The NHLBI defines bradycardia as a resting heart rate slower than 60 beats per minute. It is not always a problem.
Why is my heart rate lowest early in the night?
Deep sleep tends to happen more in the first part of the night. That is when heartbeat and breathing reach their lowest levels.
Why does my heart rate go up during REM sleep?
During REM sleep, heart rate and blood pressure rise to near waking levels. This is a normal part of the sleep cycle.
Why do athletes have such low heart rates at night?
Training makes the heart stronger, so it pumps more blood per beat. It needs fewer beats to do the same work.
Can beta blockers lower my heart rate during sleep?
Yes. Beta blockers slow the heart, and that effect continues during sleep.
Should I stop my medicine if my heart rate is low?
No. Do not stop or change any prescribed medicine on your own. Talk to your prescriber first.
Can sleep apnea cause my heart rate to drop?
Sleep apnea is associated with sharp heart-rate drops during breathing pauses. These are often followed by a quick rise when breathing restarts.
How can I tell a normal dip from an apnea-related drop?
A normal dip is smooth and steady. An apnea-related drop tends to repeat in a jagged, sawtooth pattern.
Is sleep apnea linked to heart block?
Sleep apnea is associated with brief heart block episodes during breathing pauses in some people. A cardiologist should evaluate any heart block finding.
Should I worry about a low heart rate alert from my watch?
Not by itself. Check whether you had symptoms and whether the alert came during deep sleep.
Can I change my watch’s low heart rate alert setting?
Most wearables let you set your own threshold. Ask your doctor what level makes sense for you.
Are smartwatch heart-rate readings accurate during sleep?
They are estimates and can vary by device. Use them as clues to share with your doctor.
Does SLIIIP treat bradycardia?
No. SLIIIP evaluates sleep disorders and works alongside your cardiologist or primary care doctor.
Can a home sleep test show heart rate?
Yes. A home sleep test records heart rate along with breathing and oxygen levels overnight.
When should I call 911 for a low heart rate?
Call 911 if a slow heart rate comes with fainting, chest pain, severe shortness of breath, or confusion.
What symptoms make a low heart rate more concerning?
Dizziness, fainting, unusual tiredness, shortness of breath, and confusion all deserve a doctor’s attention.
Who should I see first about a low nighttime heart rate?
Start with your primary care doctor or cardiologist. Ask about a sleep evaluation if you also snore or wake up tired.
SLIIIP’s board-certified sleep physicians can do sleep evaluations for sleep apnea. Virtual consultations in all 50 states. Home sleep tests shipped to your door.
